Apparatus and methods for coating medical devices

ABSTRACT

Embodiments of the invention include apparatus and methods for coating drug eluting medical devices. In an embodiment, the invention includes a coating apparatus including a coating application unit comprising a movement restriction structure; a fluid applicator; and an air nozzle. The apparatus can further include a rotation mechanism and an axial motion mechanism, the axial motion mechanism configured to cause movement of at least one of the coating application unit and the rotation mechanism with respect to one another. Other embodiments are also included herein.

This application claims the benefit of U.S. Provisional Application No.61/654,403, filed Jun. 1, 2012 and U.S. Provisional Application No.61/661,684, filed Jun. 19, 2012 the contents of which are hereinincorporated by reference.

FIELD OF THE INVENTION

The present invention relates to apparatus and methods for coatingmedical devices.

BACKGROUND OF THE INVENTION

Functional improvements to implantable or insertable medical devices canbe achieved by coating the surface of the device. For example, a coatingformed on the surface of the device can provide improved lubricity,improved biocompatibility, or drug delivery properties to the surface.In turn, this can improve movement of the device in the body, extend thefunctional life of the device, or treat a medical condition near thesite of implantation. However, various challenges exist for the designand use of coating apparatus designed to provide coatings to medicaldevices.

Traditional coating methods, such as dip coating, are often undesirableas they may result in flawed coatings that could compromise the functionof the device or present problems during use. These methods can alsoresult in coating inaccuracies, which can be manifested in variableamounts of the coated material being deposited on the surface of thedevice. When a drug is included in the coating material, it is oftennecessary to deliver precise amounts of the agent to the surface of thedevice to ensure that a subject receiving the coated device receives aproper dose of the agent. It has been difficult to achieve a greatdegree of accuracy using traditional coating methods and machines.

One type of insertable medical device is a balloon catheter. Ballooncatheter constructions are well known in the art and are described invarious documents, for example, U.S. Pat. Nos. 4,195,637, 5,041,089,5,087,246, 5,318,587, 5,382,234, 5,571,089, 5,776,101, 5,807,331,5,882,336, 6,394,995, 6,517,515, 6,623,504, 6,896,842, and 7,163,523.Balloon catheters generally include four portions, the balloon, cathetershaft, guide wire, and manifold. A balloon catheter generally includesan elongated catheter shaft with an inflatable balloon attached to adistal section of the catheter shaft. At a proximal end of the cathetershaft, there is typically a manifold. At the manifold end, placement ofthe catheter can be facilitated using a guide wire. Guide wires aresmall and maneuverable when inserted into an artery. Once the guide wireis moved to the target location, the catheter with balloon portion isthen fed over the guide wire until the balloon reaches the targetlocation in the vessel. The balloon is typically inserted into thearterial lumen of a patient and advanced through the lumen in anunexpanded state. The balloon is then inflated when the catheter reachestarget site resulting in application of mechanical force sufficient tocause vessel dilation. The balloon is typically inflated using a fluid,which is injected through an inflation port. The manifold can controlthe fluid introduction within shaft for expansion of the balloon. Themechanics of fluid transfer and introduction within balloons varyaccording to the specific design of the catheter, and are well known inthe art.

SUMMARY OF THE INVENTION

Embodiments of the invention include apparatus and methods for coatingdrug coated medical devices. In an embodiment, the invention includes acoating apparatus including a coating application unit comprising amovement restriction structure; a fluid applicator; and an air nozzle.The apparatus can further include a rotation mechanism and a axialmotion mechanism, the axial motion mechanism configured to causemovement of at least one of the coating application unit and therotation mechanism with respect to one another.

In an embodiment, the invention includes a coating apparatus including acoating application unit comprising a fluid applicator; a fluiddistribution bar; an air nozzle; and a rotation mechanism. The coatingapparatus can further include an axial motion mechanism, the axialmotion mechanism configured to cause movement of the coating applicationunit with respect to the rotator.

In an embodiment, the invention includes a method of coating includingrotating a balloon catheter with a rotation mechanism, the ballooncatheter comprising a balloon, contacting the balloon with a movementrestriction structure defining a channel; applying a coating solutiononto the surface of the balloon with a fluid applicator, contacting thesurface of the balloon with a fluid distribution bar, blowing a streamof a gas onto the surface of the balloon, wherein the channel limitslateral movement of the balloon.

This summary is an overview of some of the teachings of the presentapplication and is not intended to be an exclusive or exhaustivetreatment of the present subject matter. Further details are found inthe detailed description and appended claims. Other aspects will beapparent to persons skilled in the art upon reading and understandingthe following detailed description and viewing the drawings that form apart thereof, each of which is not to be taken in a limiting sense. Thescope of the present invention is defined by the appended claims andtheir legal equivalents.

BRIEF DESCRIPTION OF THE FIGURES

The invention may be more completely understood in connection with thefollowing drawings, in which:

FIG. 1 is a schematic side view of a coating apparatus in accordancewith various embodiments herein.

FIG. 2 is a schematic view of a coating application unit in accordancewith various embodiments herein.

FIG. 3 is a schematic view of a movement restriction structure inaccordance with various embodiments herein.

FIG. 4 is a schematic view of a movement restriction structure inaccordance with various embodiments herein.

FIG. 5 is a schematic view of a movement restriction structure inaccordance with various embodiments herein.

FIG. 6 is a schematic end view of a fluid distribution bar inconjunction with the balloon of a balloon catheter.

FIG. 7 is a schematic end view of a fluid applicator in conjunction withthe balloon of a balloon catheter.

FIG. 8 is a schematic end view of an air nozzle in conjunction with theballoon of a balloon catheter.

FIG. 9 is a schematic view of a coating application unit in accordancewith various embodiments herein.

FIG. 10 is a schematic view of a coating application unit in accordancewith various embodiments herein.

FIG. 11 is a schematic top view of a movement restriction structure inaccordance with various embodiments herein.

FIG. 12 is a schematic end view of a movement restriction structure inaccordance with various embodiments herein.

FIG. 13 is a schematic front view of a movement restriction structure inaccordance with various embodiments herein.

FIG. 14 is a schematic front view of a movement restriction structure inaccordance with various embodiments herein.

FIG. 15 is a schematic end view of a movement restriction structure inaccordance with various embodiments herein.

FIG. 16 is a schematic end view of a fluid applicator in accordance withvarious embodiments herein.

While the invention is susceptible to various modifications andalternative forms, specifics thereof have been shown by way of exampleand drawings, and will be described in detail. It should be understood,however, that the invention is not limited to the particular embodimentsdescribed. On the contrary, the intention is to cover modifications,equivalents, and alternatives falling within the spirit and scope of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments of the present invention described herein are notintended to be exhaustive or to limit the invention to the precise formsdisclosed in the following detailed description. Rather, the embodimentsare chosen and described so that others skilled in the art canappreciate and understand the principles and practices of the presentinvention.

All publications and patents mentioned herein are hereby incorporated byreference. The publications and patents disclosed herein are providedsolely for their disclosure. Nothing herein is to be construed as anadmission that the inventors are not entitled to antedate anypublication and/or patent, including any publication and/or patent citedherein.

Embodiments herein can be used to apply visually uniform coatings, suchas coatings including active agents, onto medical devices, such as ontothe balloons of drug coated or drug eluting balloon catheters, that havesubstantially uniform active agent concentrations along the length ofthe medical device. For example, in some embodiments, coatings can beformed with apparatus and methods wherein each section of the devicethat has been coated contains an amount of the active agent that iswithin ten percent of the average amount of active agent across allsections coated.

Referring now to FIG. 1, a schematic side view is shown of a coatingapparatus 100 in accordance with various embodiments herein. The coatingapparatus 100 is shown in conjunction with a drug coated ballooncatheter 102. The drug coated balloon catheter 102 can include acatheter shaft 104 and a balloon 106. The balloon 106 can assume adeflated configuration and an inflated configuration. The drug coatedballoon catheter 102 can include a distal end 103 and a proximal end105. The drug coated balloon catheter 102 can include a proximal endmanifold (not shown). The coating apparatus 100 can include a coatingapplication unit 108. The coating apparatus 100 can further include, insome embodiments, an axial motion mechanism 110 (axial with respect tothe axis of rotation of the balloon catheter and thus parallel to thelengthwise axis of the balloon catheter) that can function to move oneor more components of the coating application unit 108. In someembodiments, axial motion can be substantially horizontal. In otherembodiments, axial motion can be substantially vertical. In someembodiments, axial motion can be somewhere in between horizontal andvertical, depending on the orientation of the lengthwise axis of theballoon catheter. However, it will be appreciated that in otherembodiments, the coating application unit 108 can remain stationary.

Coating of the balloon 106 to make it drug coated can occur starting atthe proximal end of the balloon and proceeding to the distal end.However, in other embodiments, coating of the drug coated balloon 106can occur starting at the distal end of the balloon and proceeding tothe proximal end. In many embodiments, coating can take place with asingle pass of the coating application unit 108 with respect to theballoon. However, in other embodiments, multiple passes of the coatingapplication unit with respect to the balloon can be made.

The coating apparatus 100 can further include a fluid pump 112. Thefluid pump 112 can be, for example, a syringe pump. The fluid pump 112can be in fluid communication with components of the coating applicationunit 108 (such as the fluid applicator) and with a fluid reservoir 114.The fluid pump 112 can operate to pump a coating solution at a ratesufficient to apply about 0.5 μl to about 10 μl of the coating solutionper millimeter of length of the balloon or other device to be coated.The coating apparatus 100 can further include a rotation mechanism 116(or rotating balloon catheter fixture). The rotation mechanism 116 canbe directly or indirectly coupled to the drug coated balloon catheter inorder to rotate the drug coated balloon catheter 102 around itslengthwise (major) axis (about the central lumen of the catheter). Insome embodiments, the drug coated balloon catheter can be rotated at aspeed of between 100 and 400 rotations per minute. In some embodiments,the drug coated balloon catheter can be rotated at a speed of between200 and 300 rotations per minute.

In some embodiments, a guide wire 107, passing through the central lumenof the catheter, can extend from the distal tip of the catheter and beinserted into a distal tip support ring 109 or guide. In this manner,the guide wire 107 can be used to support the distal tip of the ballooncatheter to be coated while allowing the balloon catheter to rotatefreely.

The coating apparatus 100 can further include, in some embodiments, anaxial motion mechanism 118 which can be configured to move the drugcoated balloon catheter 102 in the direction of its lengthwise majoraxis. In some embodiments, axial motion can be substantially horizontal.In other embodiments, axial motion can be substantially vertical. Insome embodiments, axial motion can be somewhere in between horizontaland vertical, depending on the orientation of the lengthwise axis of theballoon catheter. In some embodiments, the axial motion mechanism 118can be a linear actuator. In some embodiments, the axial motionmechanism 118 can include an electric motor. The coating apparatus 100can further include a frame member 120 (in some embodiments this canalso be referred to as an axial motion support rail). The frame member120 can support other components of the coating apparatus 100 such asone or more guides 126. The frame member 120 can itself be support by aplatform 122. The coating apparatus 100 can further include a controller124 that can serve to control operation of the coating apparatus 100including, specifically, fluid pump 112, axial motion mechanism 110,rotation mechanism 116, and axial motion mechanism 118.

Referring now to FIG. 2, a schematic view of a coating application unit108 in accordance with various embodiments herein is shown. The coatingapplication unit 108 can include a movement restriction structure 202(or wobble control structure), an air nozzle 204, a fluid distributionbar 206, and a fluid applicator 208. The movement restriction structure202 can serve to limit the lateral motion (e.g., movement in a directionperpendicular to the lengthwise axis of the catheter) of the balloonduring a coating operation.

The fluid applicator 208 can serve to apply a coating solution 209 tothe surface of the balloon 212 on the drug coated balloon catheter. Insome embodiments, the fluid applicator 208 is less than or equal toabout 1 cm away from the movement restriction structure 202. In someembodiments, the air nozzle 204 is less than or equal to about 2 cm awayfrom the fluid applicator 208. The air nozzle 204 can provide a streamof a gas in order to assist in drying the coating solution after it hasbeen applied to the balloon or other medical device.

The fluid distribution bar 206 can serve to promote distribution of theapplied coating solution. For example, the fluid distribution bar 206can serve to prevent pooling of the applied coating solution. In someembodiments, the fluid distribution bar 206 can be at least about 0.5 mmaway from the fluid applicator and less than 2 cm away. In someembodiments, the fluid distribution bar 206 can be at least about 0.2 cmaway from the fluid applicator and less than 2 cm away.

In this embodiment, the coating application unit 108 can move, relativeto the balloon 212 in the direction of arrow 230. As such, during acoating operation, the movement restriction structure 202 can pass overthe balloon first, followed by the fluid applicator 208, followed by thefluid distribution bar 206, with the air nozzle last. It should beemphasized, however, that this movement is relative in the sense that insome embodiments the coating application unit 108 is moving and theballoon 212 is rotating but otherwise stationary, in some embodimentsthe balloon 212 is rotating and moving in the direction of itslengthwise axis and the coating application unit 108 is stationary, instill other embodiments both the coating application unit 108 and theballoon 212 are moving. The speed of movement of the balloon 212relative to the coating application unit 108 can vary depending on theamount of coating solution to be applied. In some embodiments the speedcan be from about 0.02 centimeters per second to about 0.2 centimetersper second.

It will be appreciated that based on the rotation of the drug coatedballoon catheter and the movement of the balloon relative to the coatingapplication unit that the path of the deposition of the coating onto theballoon follows a roughly helical path. It will be appreciated that thecombination of the rotation speed of the drug coated balloon catheterand the speed of the movement of the balloon relative to the coatingapplication unit can influence the amount of coating solution that isdeposited at any given point and the nature of the helical path. Forexample, the coating material can be deposited in helical layers thatpartially overlap one another at their edges, helical layers wherein theedge of one turn substantially meets the edge of a previous turn, andhelical layers wherein there are gaps in between subsequent helicalturns. In some embodiments, these helical patterns can be configured soas to maximize release of the active agent. For example, in someembodiments, the apparatus can be used to coat device so as to producehelical ridges of the coating material on the balloon surface.

In some embodiments, the coating application unit 108 can optionallyinclude a manifold block 210. The manifold block 210 can facilitatesupport of, and in some embodiments movement of, the components of thecoating application unit 108. In some embodiments, the components of thecoating application unit can move together as a unit during a coatingoperation. However, in other embodiments the components of the coatingapplication unit are substantially separate from one another and canmove independently. In some embodiments, the components of the coatingapplication unit are all substantially stationary during a coatingoperation.

While the components of the coating application unit 108 are shown inFIG. 2 as being within a particular plane and disposed at approximatelythe same angle with respect to the balloon 212 being coated, it will beappreciated that this is not the case with all embodiments herein. Insome embodiments, the components of the coating application unit 108 liein different planes with respect to the balloon 212 and/or thecomponents of the coating application unit 108 are disposed at differentangles (both with respect to the lengthwise axis of the balloon andradially) with respect to the balloon.

Referring now to FIG. 3, a schematic end view is shown of a movementrestriction structure 302 in accordance with various embodiments herein.The structure 302 can include a body member 306 defining a channel 304or aperture. The body member 306 can be formed of various materials suchas polymers, metals, ceramics, and the like. In a particular embodiment,the body member 306 is formed of polytetrafluoroethylene (PTFE). Thechannel 304 can have a diameter 308 that is sufficiently large so as toaccommodate the balloon of a drug coated balloon catheter in an expandedstate. In the example of FIG. 3, the channel 304 is shown as beingbounded in a radially continuous manner by the body member 306 (e.g., itis completely surrounded on all sides by the body member 306). However,it will be appreciated that in some embodiments the channel 304 is notbounded in a radially continuous manner by the body member 306.

In some embodiments the movement restriction structure can includemultiple pieces that together define a channel or aperture. Referringnow to FIG. 4, a movement restriction structure 402 is shown including abody member that includes a first piece 406 and a second piece 408 thattogether define a channel 404 or aperture. The first piece 406 andsecond piece 408 are joined together by a hinge 410 in this embodiment,however it will be appreciated that there are many ways known to thoseof skill in the art by which to hold two structure pieces in associationwith one another.

It will be appreciated that body members of movement restrictionstructures can take on many different shapes. In addition, the shape ofthe channel defined by the body member(s) can take on many differentshapes. Referring now to FIG. 5, a movement restriction structure 502 isshown including a first side piece 506 and a second side piece 508 thattogether define a channel 504 or aperture. In this case, the first sidepiece 506 and the second side piece 508 are supported by a frame member510. However, it will be appreciated that there are many different waysof supporting the first side piece 506 and the second side piece 508. Insome embodiments, one or both of the first side piece 506 and the secondside piece 508 can be spring loaded such that it is biased towardsliding inward toward the other piece. In other embodiments, one or bothof the first side piece 506 and the second side piece 508 can beadjustable and then fixed in position so as to create a channel 504 of adesired size.

Referring now to FIG. 6 a schematic end view of a fluid distribution bar606 in conjunction with the balloon 618 of a drug coated ballooncatheter 614 is shown. In some embodiments, the fluid distribution bar606 can include a support structure 608 and a shaft 610. In someembodiments, the support structure 608 can be omitted. The shaft 610 canbe formed of various materials such as polymers, metals, ceramics, andthe like. In a particular embodiment, the shaft 610 is formed ofpolytetrafluoroethylene (PTFE). The shaft 610 can be of various lengthsand diameters and can have various cross-sectional shapes. In someembodiments, the shaft 610 is from about 2 mm to about 15 cm and issubstantially circular in cross-sectional shape. In some embodiments,the shaft is about 1/16 inch in diameter. The shaft 610 is configured torest against the balloon 618 of the balloon catheter 614.

In yet other embodiments the fluid distribution bar 606 can includemultiple rods or extensions from support structure 608. Exemplary ofthese embodiments can include, but are not limited to, a comb-likestructure or a brush.

The balloon 618 is supported by the catheter shaft 616, but generallyonly at the ends of the balloon 618. Because of the limited support ofthe balloon 618 by the catheter shaft 616, the inherent flexibility ofthe balloon material and manufacturing variations, the balloon 618 maynot be perfectly round. As such, when it is being rotated during acoating operation there may be variations in the distance of the outersurface of the balloon 618 from the catheter shaft 616 of the ballooncatheter 614. If unaccounted for, this could lead to circumstances wherethe fluid distribution bar 606 does not maintain contact with thesurface of the balloon 618. As such, the shaft 610 of the fluiddistribution bar 606 can be configured to maintain contact with thesurface of the balloon 618. For example, the shaft 610 of the fluiddistribution bar 606 can be positioned such that it exerts a smalldegree of pressure against the surface of the balloon 618 such that whenan irregularity in the balloon is encountered the fluid distribution bar606 can move slightly in order to maintain contact with the balloonsurface. In some embodiments the shaft 610 of the fluid distribution bar606 is flexible to accommodate movement to stay in contact with theballoon surface. In other embodiments, the fluid distribution bar 606can be configured to pivot from where it is mounted in order toaccommodate movement to stay in contact with the balloon surface.

While the shaft 610 of the fluid distribution bar 606 is shown in FIG. 6as contacting the top of the balloon 618 and thus exerting a pressuredownward in the direction of arrow 612, it will be appreciated that inother embodiments the surface of the balloon 618 can be contacted atother points along its surface, such as on the sides or on the bottom.

Referring now to FIG. 7, a schematic end view of a fluid applicator 708in conjunction with the balloon 718 of a drug coated balloon catheter714 is shown in accordance with an embodiment of the invention. Thefluid applicator 708 can include a shaft 706 and an orifice 704. In someembodiments, the fluid applicator 708 can be a pipette. Fluid, such as acoating solution, can travel through the shaft 706 of the fluidapplicator 708 in order to be deposited on the surface of the balloon718 of the drug coated balloon catheter 714. The shaft 706 is configuredto rest against the balloon 718 of the balloon catheter 714. The balloon718 is supported by the catheter shaft 716, but generally only at theends of the balloon 718. Because of the limited support of the balloon718 by the catheter shaft 716, the inherent flexibility of the balloonmaterial and manufacturing variations, the balloon 718 may not beperfectly round. As such, when it is being rotated during a coatingoperation there may be variations in the distance of the outer surfaceof the balloon 718 from the catheter shaft 716 of the balloon catheter714. If unaccounted for, this could lead to circumstances where thefluid applicator 708 does not maintain contact with the surface of theballoon 718. As such, the shaft 706 of the fluid applicator 708 can beconfigured to maintain contact with the surface of the balloon 718. Forexample, the shaft 706 of the fluid applicator 708 can be positionedsuch that it exerts a small degree of pressure against the surface ofthe balloon 718 such that when an irregularity in the balloon 718 isencountered the fluid applicator 708 can move slightly in order tomaintain contact with the balloon surface. In some embodiments the shaft706 of the fluid applicator 708 is flexible to accommodate movement tostay in contact with the balloon surface. In other embodiments, thefluid applicator 708 can be configured to pivot from where it is mountedin order to accommodate movement to stay in contact with the balloonsurface. In other embodiments, the fluid applicator may not be in directcontact with the balloon surface but situated closely, for examplewithin 1 millimeter.

While the shaft 706 of the fluid applicator 708 is shown in FIG. 7 ascontacting the upper right side (approximately equivalent to an areabetween the 1 and 2 position of a clock face) of the balloon 718, itwill be appreciated that in other embodiments the surface of the balloon718 can be contacted at other points along its surface. For example, insome embodiments, the very top of the balloon 718 can be contacted bythe fluid applicator 708.

In some embodiments the fluid distribution bar 606 and the fluidapplicator 708 can be configured such that the shaft 610 of the fluiddistribution bar 606 contacts the surface of the balloon atapproximately the same point radially along the surface of the balloonas the shaft 706 of the fluid applicator 708. In some embodiments, thefluid distribution bar 606 and the fluid applicator 708 can beconfigured such that the shaft 610 of the fluid distribution bar 606contacts the surface of the balloon within at least 90 degrees radiallyalong the surface of the balloon as the shaft 706 of the fluidapplicator 708.

Referring now to FIG. 8, a schematic end view of an air nozzle 804 inconjunction with the balloon 818 of a drug coated balloon catheter 814is shown. The air nozzle 804 can include an orifice 806. A gas suchnitrogen, ambient air or another gas can be directed to flow out of theorifice 806 and towards the balloon 818 of the drug coated ballooncatheter 814. In some embodiments, the gas can be heated. For example,in some embodiments the gas can be from about 50 to about 70 degreesCelsius. While the orifice 806 of the air nozzle 804 is shown in FIG. 8as directing air to the top of the balloon 818, it will be appreciatedthat in other embodiments the air nozzle 804 and orifice 806 can beconfigured to direct air at other parts of the balloon 818 such as, butnot limited to, the sides or the bottom.

Referring now to FIG. 9, a schematic view of a coating application unitin accordance with various embodiments herein is shown. The coatingapplication unit 900 can include a movement restriction structure 902, afirst air nozzle 914, a fluid applicator 908, and a second air nozzle904. The first air nozzle 914 is disposed on one side of the fluidapplicator 908 and the second air nozzle 904 is disposed on the otherside of the fluid applicator 908. In some embodiments the first airnozzle 914 can act to avoid pooling of the coating at the fluidapplicator 908. In some embodiments the second air nozzle 904 can act toavoid pooling of the coating fluid at the fluid applicator 908. Thefluid applicator 908 can serve to apply a coating solution 909 to thesurface of the balloon on the drug coated balloon catheter. Otherembodiments can include three or more air nozzles.

In this embodiment, the coating application unit 900 can move, relativeto the balloon 912 in the direction of arrow 930. As such, during acoating operation, the movement restriction structure 902 can pass overthe balloon first. It should be emphasized, however, that this movementis relative in the sense that in some embodiments the coatingapplication unit 900 is moving and the balloon 912 is rotating butotherwise stationary, in some embodiments the balloon 912 is rotatingand moving in the direction of its lengthwise axis and the coatingapplication unit 900 is stationary, in still other embodiments both thecoating application unit 900 and the balloon 912 are moving.

It will be appreciated that the coating solution can be applied on tothe balloon in various ways including, but not limited to, spraying(including both ultrasonic spraying and conventional sprayingtechniques), dribbling, blade coating, contact printing, drop coating,or the like. In some embodiments, the fluid applicator can include afluid spray nozzle. Referring now to FIG. 10, a schematic view of acoating application unit in accordance with various embodiments hereinis shown. The coating application unit 1000 can include a movementrestriction structure 1002, an air nozzle 1004, a fluid distribution bar1006, and a fluid spray nozzle 1008. The fluid spray nozzle 1008 canserve to apply a coating solution 1009 to the surface of the balloon1012 on the drug coated balloon catheter. In some embodiments there is asmall gap between the fluid spray nozzle 1008 and the balloon 1012. Forexample, the gap can be between 1 millimeter and 10 centimeters. In someembodiments, multiple fluid applicators and/or spray nozzles can beused.

In this embodiment, the coating application unit 1000 can move, relativeto the balloon 1012 in the direction of arrow 1030. As such, during acoating operation, the movement restriction structure 1002 can pass overthe balloon first. It should be emphasized, however, that this movementis relative in the sense that in some embodiments the coatingapplication unit 1000 is moving and the balloon 1012 is rotating butotherwise stationary, in some embodiments the balloon 1012 is rotatingand moving in the direction of its lengthwise axis and the coatingapplication unit 1000 is stationary, in still other embodiments both thecoating application unit 1000 and the balloon 1012 are moving.

FIG. 11 is a schematic top view of a movement restriction structure inaccordance with various embodiments herein. The structure 1102 caninclude a first body member 1104 and a second body member 1106. Thefirst and second body members 1104, 1106 can be formed of variousmaterials such as polymers, metals, ceramics, and the like. The firstand second body members 1104, 1106 can function together to restrictmovement of a balloon 1118 to be coated. The first and second bodymembers 1104, 1106 can be separated from one another by a distance 1108that is greater than or equal to the diameter of the balloon 1118. Insome embodiments, the distance 1108 is approximately equal to theballoon 1118. In some embodiments, the distance 1108 is between about 3millimeters and about 10 millimeters.

FIG. 12 is a schematic end view of the movement restriction structure1102. The first body member 1104 can include a curved segment 1142 andan end 1144. The curved segment 1142 can define a portion of a channelwhich can surround at least a portion of the balloon 1118, therebyrestricting its movement. In some embodiments, the second body member1106 can be formed similarly but with a different orientation so thattogether the first body member 1104 and the second body member 1106 caneffectively restrict movement of the balloon 1118. For example, the end1146 of the second body member 1106 can be pointed upward instead ofdownward. FIG. 13 is a schematic front view of the movement restrictionstructure 1102 that shows the differing orientations of the first bodymember 1104 and the second body member 1106.

It will be appreciated that the balloon can be loaded into the movementrestriction structure in various ways. For example, in some embodiments,the balloon catheter can simply be threaded through the movementrestriction structure before or after being connected with otherportions of the apparatus in preparation for coating. In otherembodiments, the movement restriction structure itself can bemanipulated in order to load the balloon. For example, in someembodiments, the movement restriction structure can be rotated into anopen orientation in order to accommodate loading the balloon from theside. Then, in some embodiments, the movement restriction structure canbe rotated from the open orientation to a closed orientation in order tolock the balloon in place. Referring now to FIG. 14, a schematic frontview of the movement restriction structure 1102 is shown illustrating anopen orientation. In this view, it can be seen that the first bodymember 1104 and the second body member 1106 are rotated approximately 90degrees from their respective positions in FIG. 13. The balloon 1118 canbe slid out from between the first and second body members 1104, 1106when the movement restriction structure 1102 is in this orientation. Inoperation, then, a new balloon to be coated can be slid back in betweenthe first and second body members 1104, 1106 and then the body memberscan be rotated in the direction of arrows 1150 and 1152 to put themovement restriction structure 1102 into the closed position(illustrated in FIG. 13) where the balloon 1118 is locked in place. Insome embodiments, the first and second body members 1104, 1106 can berotated in either direction. The first and second body members 1104,1106 can be rotated together around a single axis or independently fromone another around two separate axes.

It will be appreciated that body members of movement restrictionsstructures in accordance with embodiments herein can also includevarious other features. Referring now to FIG. 15, a schematic end viewof portions of a movement restriction structure 1500 are shown inaccordance with various embodiments herein. The movement restrictionstructure 1500 can include a first body member 1502. The first bodymember 1502 can include a curved segment 1504 and an end 1508. Thecurved segment 1504 can define a portion of a channel which can surroundat least a portion of the balloon 1518, thereby restricting theballoon's 1518 movement, in conjunction with a second body member (notshown in this view). The first body member 1502 can also include analignment lip 1506 adjacent to the end 1508. The alignment lip 1506 caninclude a surface 1510 that is angled away from the channel defined bythe curved segment 1504. The alignment lip 1506 can aid in positioningthe balloon 1518 within the channel formed by the curved segment 1504.For example, when the first body member 1502 is rotated starting fromthe open position, if the balloon 1518 is slightly out of position bybeing too close to the end 1508, the surface 1510 of the alignment lip1506 will contact the balloon 1518 surface and cause the balloon 1518 tomove into alignment with the channel.

It will be appreciated that fluid applicators can take on variousconfigurations in accordance with embodiments herein. FIG. 16 is aschematic end view of a fluid applicator 1600 in accordance with variousembodiments herein. The fluid applicator 1600 can include a shaft 1602and an orifice 1608. The orifice 1608 can be located along the shaft1602 at a position other than at the distal end 1620 of the shaft 1602.Fluid 1604, such as a coating solution, can pass from the fluidapplicator 1600 through the orifice 1608 in order to be deposited on thesurface of the balloon. The segment 1606 of the shaft 1602 that extendsbeyond where the orifice 1608 is located can be curved, in someembodiments, in order to form part of a channel which can serve tomaintain the position of the balloon relative to the fluid applicator1600. In some embodiments, segment 1606 can be disposed between theorifice 1608 and the distal end 1620 of the shaft 1602.

It will be appreciated that coating solutions applied onto balloons caninclude various components including, but not limited to, one or moreactive agents, carrier agents and/or solvents, polymers (includingdegradable or non-degradable polymers), excipients, and the like. Therelative amounts of the components of the coating solution will dependon various factors including the desired amount of active agent to beapplied to the balloon and the desired release rate of the active agent.

Embodiments herein include methods of applying coatings onto ballooncatheters. In an embodiment, the method can include rotating a ballooncatheter with a rotation mechanism, the balloon catheter comprising aballoon, contacting the balloon with a movement restriction structuredefining a channel, wherein the channel limits lateral movement of theballoon, applying a coating solution onto the surface of the balloonwith a fluid applicator (such as through direct contact with a fluidapplicator), contacting the surface of the balloon with a fluiddistribution bar, and blowing a stream of a gas onto the surface of theballoon. In some embodiments, the balloon catheter can be rotated at aspeed of between 100 and 400 rotations per minute.

In some embodiments, the method can include moving the fluid applicatorrelative to the lengthwise axis of the drug eluting balloon catheter. Insome embodiments, the method can include moving the drug eluting ballooncatheter along its lengthwise axis relative to the fluid applicator,fluid distribution bar, and movement restriction structure.

It should be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the content clearly dictates otherwise. Thus, for example,reference to a composition containing “a compound” includes a mixture oftwo or more compounds. It should also be noted that the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

It should also be noted that, as used in this specification and theappended claims, the phrase “configured” describes a system, apparatus,or other structure that is constructed or configured to perform aparticular task or adopt a particular configuration to. The phrase“configured” can be used interchangeably with other similar phrases suchas arranged and configured, constructed and arranged, constructed,manufactured and arranged, and the like.

All publications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thisinvention pertains. All publications and patent applications are hereinincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated by reference.

The invention has been described with reference to various specific andpreferred embodiments and techniques. However, it should be understoodthat many variations and modifications may be made while remainingwithin the spirit and scope of the invention.

1. A coating apparatus comprising: a coating application unit comprisinga movement restriction structure; a fluid applicator; an air nozzle; anda rotation mechanism; and an axial motion mechanism, the axial motionmechanism configured to cause movement of at least one of the coatingapplication unit and the rotation mechanism with respect to one another.2. (canceled)
 3. (canceled)
 4. (canceled)
 5. The coating apparatus ofclaim 1, further comprising a fluid reservoir in fluid communicationwith the fluid applicator;
 6. The coating apparatus of claim 1, furthercomprising a fluid pump in fluid communication with the fluid reservoirand the fluid applicator.
 7. (canceled)
 8. (canceled)
 9. The coatingapparatus of claim 1, the fluid applicator comprising a shaft includinga curved portion and an orifice, wherein the curved portion of the shaftis disposed between the orifice and the distal end of the shaft. 10.(canceled)
 11. The coating apparatus of claim 1, the coating applicationunit further comprising a fluid distribution bar.
 12. The coatingapparatus of claim 1, wherein the movement restriction structureprevents lateral movement of the drug eluting balloon catheter as it isbeing rotated by the rotation mechanism.
 13. The coating apparatus ofclaim 1, the movement restriction structure defining a channelsurrounding the drug eluting balloon catheter.
 14. The coating apparatusof claim 1, the movement restriction structure defining a channel havinga size sufficient to surround the balloon of the drug eluting ballooncatheter when the balloon is in an expanded state.
 15. The coatingapparatus of claim 1, the movement restriction structure defining achannel surrounded by the movement restriction structure in a radiallycontinuous manner.
 16. The coating apparatus of claim 1, the movementrestriction structure defining a channel surrounded by the movementrestriction structure in a radially non-continuous manner.
 17. Thecoating apparatus of claim 1, the movement restriction structurecomprising a first body member and a second body member, the first bodymember defining a first portion of a channel and the second body memberdefining a second portion of a channel, the first body member and secondbody member separated from one another by a distance of at least 3millimeters.
 18. The coating apparatus of claim 1, the movementrestriction structure comprising a first body member and a second bodymember, the first body member defining a first portion of a channel andthe second body member defining a second portion of a channel, the firstbody member and second body member configured to rotate between a closedposition where a balloon is locked in place in the channel and an openposition where the balloon is released.
 19. The coating apparatus ofclaim 18, wherein the first body member and second body member rotatetogether around a single axis.
 20. The coating apparatus of claim 18,wherein the first body member and second body member rotateindependently from one another.
 21. The coating apparatus of claim 1,wherein the axial motion mechanism creates horizontal motion.
 22. Thecoating apparatus of claim 1, wherein the axial motion mechanism createsvertical motion.
 23. A coating apparatus comprising: a coatingapplication unit comprising a fluid applicator; a fluid distributionbar; an air nozzle; and a rotation mechanism; and an axial motionmechanism, the axial motion mechanism configured to cause movement ofthe coating application unit with respect to the rotator.
 24. Thecoating apparatus of claim 23, the coating application unit furthercomprising a movement restriction structure.
 25. A method of coatingcomprising: rotating a drug eluting balloon catheter with a rotationmechanism, the drug eluting balloon catheter comprising a balloon;contacting the balloon with a movement restriction structure defining achannel, wherein the channel limits lateral movement of the balloon;applying a coating solution onto the surface of the balloon with a fluidapplicator; contacting the surface of the balloon with a fluiddistribution bar; and blowing a stream of a gas onto the surface of theballoon.)
 26. The method of claim 25, wherein the drug eluting ballooncatheter is rotated at a speed of between 100 and 400 rotations perminute.
 27. (canceled)
 28. (canceled)
 29. (canceled)